Study Of Phthalate Exposure And Impacts On Children’s Growth And Development

Phthalates are environmental endocrine disruptors that are widely used in commercial products, such as building materials, household furnishings, cosmetics, and medical devices. In this study, a novel technique was developed for the analysis of phthalate esters in soil near an electronics manufacturing facility and from a non-industrialized area in central China’s Hubei Province. We also detected the serum concentrations of phthalate metabolites and collected epidemiological data of children in the district. Furthermore, we explored the factors affecting internal exposure to phthalates and investigated the relationship between phthalate metabolites and thyroid hormones and growth.Part1:The study of the method to analysis of phthalate esters in soil using gas purge microsyringe extraction and gas chromatographyObjective:This study was conducted to introduce a new gas purge microsyringe extraction and gas chromatography (GP-MSE/GC) method for determining phthalate esters (PAEs) in soil samples, to investigate the concentration, composition, and distribution of six phthalates in soil near an electronics facility and in a non-industrialized area, and to discuss the congener profiles and influence of the electronics industry on PAE accumulation in soil.Methods:Various operational conditions about for GP-MSE were systematically investigated. In December2013, soil samples (n=142) were collected within1km of an electronics factory in Xiangyang. Sampling locations were as follows:residential areas (n=46), roadsides (n=33), farmland (n=32), and non-cultivated fields (n=31). For comparison,145soil samples were collected from a non-industrialized area (control)10km from the electronics factory.Results:GP-MSE conditions were as follows:the gas flow rate was2.0mL/min, extraction time was4min, extracting solvent was10μL of hexane/acetone (1:1, v:v), and temperatures of the sample and extracting solvent were280℃and-4℃, respectively. PAE concentrations were significantly higher in the industrialized area than in the non-industrialized area.DBP and DEHP concentrations were three-and ten-fold higher, respectively, near the electronics factory than in the residential areas; in roadside fields, these PAEs were and seven-and two-fold higher, respectively, near the factory than in roadside fields. Concentrations of DMP, DEP, and DBP concentrations in farmland soil were significantly higher near the electronics factory than in the non-industrialized area. In non-cultivated fields, DEP and DBP concentrations were higher near the factory; DMP and DnOP concentrations were also significantly higher, but BBP concentration did not differ between the two areas.Conclusion:This method provides the advantages of is simple to conduct operation, allows efficient sample pretreatment, and rapid analysis, and is suitable for determining PAE concentrations in a large number of soils. Electronics manufacturing can lead to elevated concentrations of PAEs in soils, and; without effective prevention and protective measures, that PAE pollution will likely become a more severe larger problem if effective prevention and protective measuresare not established. Part2:Association between serum phthalate metabolites during childhood and thyroid function, insulin-like growth factor1, and growthObjective:To explore the factors affecting internal exposure to phthalates and examine the associations between serum phthalate metabolite concentrations and thyroid and growth parameters for children’s health. Methods:The serum concentrations of phthalate metabolites in children aged5-7years in the area were detected using high performance liquid chromatography-tandem mass spectrometry (HPLC/MS/MS). Information about family status, living environment, and lifestyle was collected using a questionnaire; chi-square tests were conducted to compare the distribution of different characteristics by phthalic acid monoester levels, and the significant variables were included in logistic regression statistically significantly analyses. Furthermore, serum concentration of thyroid hormone concentrations and growth were measured. Multivariate linear regression analysis was used to explore relationships between phthalate metabolite concentrations and serum hormone levels or growth estimates; sex and age were included as covariates in the analyses of hormone levels and growth estimates.Results:MBP concentrations were the highest (60.01±70.40ng/mL), followed (in decreasing order) by MMP, MEP, MEHHP, MEOHP, MEHP, MBzP, and MOP (0.29±0.39ng/mL).The logistic regression models showed that residence, building types, types of decorative materials in children’s rooms, use of plastic food packaging, and the source of drinking water were significant factors for most of the phthalate metabolites. In multivariate adjusted models, increased loge MEOHP and MOP concentrations were associated with FT3on the aggression (0.258,95%CI:0.069to0.447;0.201,95%CI:0.052to0.351, respectively), and MBP and MBzP concentrations were associated with T4(-0.739,95%CI:-1.366to1.113;-0.562,95%CI:-1.075to-0.049, respectively). MMP and MBP concentrations were associated with insulin-like growth factor-1(-0.082,95%CI:-0.164to-0.001;-0.132,95%CI:-0.209to-0.055, respectively). Body mass index and waist circumference were also positively associated with serum E mPAE concentrations.Conclusion:Our results suggest that exposure to phthalic acid esters in preschool children might interfere with thyroid and growth hormones and affect body mass index and waist circumference.